Diction (Latin: dictionem (nom. dictio), "a saying, expression, word"), in its original, primary meaning, refers to the writer's or the speaker's distinctive vocabulary choices and style of expression in a poem or story. A secondary, common meaning of "diction" means the distinctiveness of speech, the art of speaking so that each word is clearly heard and understood to its fullest complexity and extremity, and concerns pronunciation and tone, rather than word choice and style. This secondary sense is more precisely and commonly expressed with the term enunciation, or with its synonym articulation.
Diction has multiple concerns, of which register is foremost—another way of saying this is whether words are either formal or informal in the social context. Literary diction analysis reveals how a passage establishes tone and characterization, e.g. a preponderance of verbs relating physical movement suggests an active character, while a preponderance of verbs relating states of mind portrays an introspective character. Diction also has an impact upon word choice and syntax.
Aristotle, in The Poetics (20) states that "Diction comprises eight elements: Phoneme, Syllable, Conjunction, Connective, Noun, Verb, Inflection, and Utterance. However, Epps states that in this passage "the text is so confused and some of the words have such a variety of meanings that one cannot always be certain what the Greek says, much less what Aristotle means."
In literature
Diction is usually judged with reference to the prevailing standards of proper writing and speech and is seen as the mark of quality of the writing. It is also understood as the selection of certain words or phrases that become peculiar to a writer.
Forms of diction include: Archaic Diction (diction that is antique, that is rarely used), High Diction (lofty sounding language), and Low Diction (everyday language). Each of these forms are to enhance the meaning or artistry of an author's work.